1. Field of the Invention
This invention generally relates to a system with moveable light sources and, more particularly, to a system for controlling the moveable light sources during use.
2. Description of Related Art
There are many types of lights. A popular high intensity light includes a discharge lamp. A lamp typically comprises a quartz tube filled with gas. The gas ambient is exposed to a pair of electrodes. During times when current is passed between the electrode pair, the gas is excited to a plasma state which causes photon emissions. Plasma excitation results in high intensity light emission from the lamp.
U.S. Pat. No. 5,128,596 to Shimazu et al. relates to a gaseous-discharge lamp having a reflector in the interior thereof U.S. Pat. No. 4,339,789 to Husby et al. relates to a flood light aiming method using a laser. Both of these patents are hereby incorporated by reference.
In many applications, lamp discharge must be moved in order to illuminate a target area on or near a display surface. For example, the display surface may include a stage containing one or more performers. To draw attention to the performers, it is desirable to forward the lamp output on only the target area containing one or more performers.
A luminaire can be used to move the lamp output and the characteristics of that output. For example, a luminaire may include a yoke, means for movably suspending the yoke from a support, and a housing movably connected to the yoke. A lamp may be secured within the housing, also containing possibly a light dispersion lens. Still further, the housing may include color filters and/or a disc of cast material. A pattern may be formed upon the material to allow the lamp output to change not only in color, but to project a pattern upon the target area.
The lamp-containing luminaire is moveably mounted proximate to the display surface. The luminaire periodically controls lamp output to illuminate an isolated target area within the display surface. For example, lamp output is desirably programmed to activate and deactivate at certain times so that a target area in which a performer stands is periodically illuminated. Thus, once the moving mechanism of the luminaire establishes the point in which lamp output impinges the target area, it may remain in that position, for example, throughout a stage performance.
Aiming the lamp output upon the target area to establish the initial position is, unfortunately, sometimes difficult. Typically, the lamp is aimed prior to the performance when ambient light conditions are not condusive for detecting light output. For example, most performances in which a lamp is used occur when the ambient light is substantially reduced if not eliminated. This allows the lamp output to readily discern and focus upon the performer placed in the target area. Unfortunately, the lamp is aimed to that target area prior to performance, and prior to the darkening of the ambient light. When light exists in the room, or daylight illuminates the display surface, operators cannot easily determine where the lamp output illuminates the display surface, especially if the display surface is a significant distance from the lamp. An operator may therefore be required to maintain the lamp active during set up for a substantially long period of time in order to properly aim the lamp. Moving the lamp about the yoke and/or support may require additional time, all of which adds to the duration in which the lamp must be active throughout the aiming procedure.
Light output involving lamps of the "discharge" variety mandate that the lamp output be extremely intense. To illuminate a target area that is a significant distance from the lamp requires a very high energy output. To maintain this high output, substantial heat oftentimes exceeding 1000.degree. F. will develop within the lamp components during a normal activation sequence. Over time, the heat will degrade those components, and eventually, cause the lamp to fail.
It would therefore be desirable to have a moveable light fixture containing a light source. An improvement to the light fixture, and embodied light source, involves accurate aiming of that source. A light fixture aiming device and/or light source aiming device is thereby needed which does not require activation of the light. More specifically, an improved mechanism and method is needed for accurately aiming what will be the light output without actually having to turn on the light. Further, the improved mechanism is one that can be used regardless of ambient light conditions.
In addition, it is desirable to be able to control multiple lights. Specifically, during an event such as a music performance, it is desirable to be able to control the color, shape, and position of multiple lights. Such controls are somewhat difficult to implement in many events since operators typically are not afforded much time to input control data. Thus an improved system and method is needed for allowing multiple lights to be controlled.